Conventionally, for example, a ceramic honeycomb structure, having a plurality of through holes, with a polygonal cross sectional shape has been known. Such a honeycomb structure is used for a diesel particulate filter and so on. Such a honeycomb structure is produced by making a green honeycomb molded body by molding a ceramic raw material powder by an extrusion method and so on, and by closing and calcining this green honeycomb molded body after being cut in a desired length. Then, in Patent Literature 1, the production method for the honeycomb structure has been disclosed. In Patent Literature 1, by pressing a closing member with a piston against one end of the honeycomb structure arranged in a cylinder, the closing member is supplied to the end of through holes of the honeycomb structure, and the through holes are closed.